About 85% through porting over MySQL on duplicate key functionality.

lib/ar-extensions/import/mysql.rb

@@ -0,0 +1,50 @@
+module ActiveRecord::Extensions::ConnectionAdapters::MysqlAdapter # :nodoc:
+
+  include ActiveRecord::Extensions::Import::ImportSupport  
+  include ActiveRecord::Extensions::Import::OnDuplicateKeyUpdateSupport
+    
+  # Returns a generated ON DUPLICATE KEY UPDATE statement given the passed
+  # in +args+. 
+  def sql_for_on_duplicate_key_update( table_name, *args ) # :nodoc:
+    sql = ' ON DUPLICATE KEY UPDATE '
+    arg = args.first
+    if arg.is_a?( Array )
+      sql << sql_for_on_duplicate_key_update_as_array( table_name, arg )
+    elsif arg.is_a?( Hash )
+      sql << sql_for_on_duplicate_key_update_as_hash( table_name, arg )
+    elsif arg.is_a?( String )
+      sql << arg
+    else
+      raise ArgumentError.new( "Expected Array or Hash" )
+    end
+    sql
+  end
+
+  def sql_for_on_duplicate_key_update_as_array( table_name, arr )  # :nodoc:
+    results = arr.map do |column|
+      qc = quote_column_name( column )
+      "#{table_name}.#{qc}=VALUES(#{qc})"        
+    end
+    results.join( ',' )
+  end
+  
+  def sql_for_on_duplicate_key_update_as_hash( table_name, hsh ) # :nodoc:
+    sql = ' ON DUPLICATE KEY UPDATE '
+    results = hsh.map do |column1, column2|
+      qc1 = quote_column_name( column1 )
+      qc2 = quote_column_name( column2 )
+      "#{table_name}.#{qc1}=VALUES( #{qc2} )"
+    end
+    results.join( ',')
+  end
+
+  #return true if the statement is a duplicate key record error
+  def duplicate_key_update_error?(exception)# :nodoc:
+    exception.is_a?(ActiveRecord::StatementInvalid) && exception.to_s.include?('Duplicate entry')
+  end
+
+end
+
+ActiveRecord::ConnectionAdapters::MysqlAdapter.class_eval do
+  include ActiveRecord::Extensions::ConnectionAdapters::MysqlAdapter
+end

test/models/topic.rb

@@ -1,6 +1,7 @@
 class Topic < ActiveRecord::Base
   validates_presence_of :author_name
   has_many :books
+  belongs_to :parent, :class_name => "Topic"
   
   composed_of :description, :mapping => [ %w(title title), %w(author_name author_name)], :allow_nil => true, :class_name => "TopicDescription"
 end

test/mysql/import_test.rb

@@ -0,0 +1,141 @@
+require File.expand_path(File.dirname(__FILE__) + '/../test_helper')
+require "ar-extensions/import/mysql"
+
+describe "#import with :on_duplicate_key_update option (mysql specific functionality)" do
+  macro(:perform_import){ raise "supply your own #perform_import in a context below" }
+  
+  assertion(:should_not_update_fields_not_mentioned) do
+    assert_equal "John Doe", @topic.reload.author_name
+  end
+  
+  assertion(:should_update_fields_mentioned) do
+    perform_import
+    assert_equal "Book - 2nd Edition", @topic.reload.title
+    assert_equal "johndoe@example.com", @topic.reload.author_email_address
+  end
+  
+  assertion(:should_update_fields_mentioned_with_hash_mappings) do
+    perform_import
+    assert_equal "johndoe@example.com", @topic.reload.title
+    assert_equal "Book - 2nd Edition", @topic.reload.author_email_address
+  end
+  
+  assertion(:should_update_foreign_keys) do
+    perform_import
+    assert_equal 57, @topic.reload.parent_id
+  end
+  
+  context "given columns and values with :validation checks turned off" do
+    let(:columns){  %w( id title author_name author_email_address parent_id ) }
+    let(:values){ [ [ 99, "Book", "John Doe", "john@doe.com", 17 ] ] }
+    let(:updated_values){ [ [ 99, "Book - 2nd Edition", "Author Should Not Change", "johndoe@example.com", 57 ] ] }
+  
+    macro(:perform_import) do
+      Topic.import columns, updated_values, :on_duplicate_key_update => update_columns, :validate => false
+    end
+    
+    setup do
+      Topic.import columns, values, :validate => false
+      @topic = Topic.find 99
+    end
+    
+    context "using string column names" do
+      let(:update_columns){ [ "title", "author_email_address", "parent_id" ] }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned
+      should_update_foreign_keys
+    end
+  
+    context "using symbol column names" do
+      let(:update_columns){ [ :title, :author_email_address, :parent_id ] }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned
+      should_update_foreign_keys
+    end
+    
+    context "using string hash map" do
+      let(:update_columns){ { "title" => "title", "author_email_address" => "author_email_address", "parent_id" => "parent_id" } }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned
+      should_update_foreign_keys
+    end
+  
+    context "using string hash map, but specifying column mismatches" do
+      let(:update_columns){ { "title" => "author_email_address", "author_email_address" => "title", "parent_id" => "parent_id" } }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned_with_hash_mappings
+      should_update_foreign_keys
+    end
+  
+    context "using symbol hash map" do
+      let(:update_columns){ { :title => :title, :author_email_address => :author_email_address, :parent_id => :parent_id } }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned
+      should_update_foreign_keys
+    end
+  
+    context "using symbol hash map, but specifying column mismatches" do
+      let(:update_columns){ { :title => :author_email_address, :author_email_address => :title, :parent_id => :parent_id } }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned_with_hash_mappings
+      should_update_foreign_keys
+    end
+  end
+  
+  context "given array of model instances with :validation checks turned off" do
+    macro(:perform_import) do
+      @topic.title = "Book - 2nd Edition"
+      @topic.author_name = "Author Should Not Change"
+      @topic.author_email_address = "johndoe@example.com"
+      @topic.parent_id = 57
+      Topic.import [@topic], :on_duplicate_key_update => update_columns, :validate => false
+    end
+    
+    setup do
+      @topic = Generate(:topic, :id => 99, :author_name => "John Doe", :parent_id => 17)
+    end
+    
+    context "using string column names" do
+      let(:update_columns){ [ "title", "author_email_address", "parent_id" ] }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned
+      should_update_foreign_keys
+    end
+
+    context "using symbol column names" do
+      let(:update_columns){ [ :title, :author_email_address, :parent_id ] }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned
+      should_update_foreign_keys
+    end
+    
+    context "using string hash map" do
+      let(:update_columns){ { "title" => "title", "author_email_address" => "author_email_address", "parent_id" => "parent_id" } }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned
+      should_update_foreign_keys
+    end
+
+    context "using string hash map, but specifying column mismatches" do
+      let(:update_columns){ { "title" => "author_email_address", "author_email_address" => "title", "parent_id" => "parent_id" } }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned_with_hash_mappings
+      should_update_foreign_keys
+    end
+
+    context "using symbol hash map" do
+      let(:update_columns){ { :title => :title, :author_email_address => :author_email_address, :parent_id => :parent_id } }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned
+      should_update_foreign_keys
+    end
+
+    context "using symbol hash map, but specifying column mismatches" do
+      let(:update_columns){ { :title => :author_email_address, :author_email_address => :title, :parent_id => :parent_id } }
+      should_not_update_fields_not_mentioned
+      should_update_fields_mentioned_with_hash_mappings
+      should_update_foreign_keys
+    end
+  end
+  
+end

test/schema/mysql_schema.rb

@@ -0,0 +1,32 @@
+ActiveRecord::Schema.define do
+ 
+  create_table :test_myisam, :options=>'ENGINE=MyISAM', :force=>true do |t|
+    t.column :my_name, :string, :null=>false
+    t.column :description, :string
+  end
+  
+  create_table :test_innodb, :options=>'ENGINE=InnoDb', :force=>true do |t|
+    t.column :my_name, :string, :null=>false
+    t.column :description, :string
+  end
+
+  create_table :test_memory, :options=>'ENGINE=Memory', :force=>true do |t|
+    t.column :my_name, :string, :null=>false
+    t.column :description, :string
+  end
+  
+  create_table :books, :options=>'ENGINE=MyISAM', :force=>true do |t|
+    t.column :title, :string, :null=>false
+    t.column :publisher, :string, :null=>false, :default => 'Default Publisher'
+    t.column :author_name, :string, :null=>false
+    t.column :created_at, :datetime
+    t.column :created_on, :datetime
+    t.column :updated_at, :datetime
+    t.column :updated_on, :datetime
+    t.column :publish_date, :date
+    t.column :topic_id, :integer
+    t.column :for_sale, :boolean, :default => true
+  end
+  execute "ALTER TABLE books ADD FULLTEXT( `title`, `publisher`, `author_name` )"
+
+end

test/test_helper.rb

@@ -22,6 +22,21 @@ class ActiveSupport::TestCase
   self.use_transactional_fixtures = true
   
   class << self
+    def assertion(name, &block)
+      mc = class << self ; self ; end
+      mc.class_eval do
+        define_method(name) do
+          it(name, &block)
+        end
+      end
+    end
+
+    def macro(name, &block)
+      class_eval do
+        define_method(name, &block)
+      end
+    end
+    
     def describe(description, toplevel=nil, &blk)
       text = toplevel ? description : "#{name} #{description}"
       klass = Class.new(self)